Rust Style Formatting and Static Analysis

Based on the rustfmt Book, Clippy Book, Edition Guide, and Error Code Index.

Capability Boundaries

✅ Strengths

1. Stable rustfmt configuration (edition, max_width, tab_spaces, use_field_init_shorthand, etc.)
2. Clippy lint system — all 10 lint groups: correctness, suspicious, style, complexity, perf, pedantic, restriction, cargo, nursery, internal
3. clippy.toml configuration (msrv, arithmetic-side, cognitive-complexity-threshold, avoid-breaking-exported-api, etc.)
4. #[expect(...)] attribute (Rust 1.81+) for CI-enforced lint expectations
5. Lint priority ordering for layered policy
6. Production CI lint policy (deny/warn/allow decisions per group)
7. Edition migration (2015→2018→2021→2024, key changes per edition and cargo fix commands)
8. Compiler error code interpretation (rustc --explain, common error codes reference table)

⚠️ Prerequisites

1. Rust toolchain installed and configured